For most homes in the United States, grid outages are infrequent and short-lived, and a batteryless grid-tied system is the most efficient and economical choice. The utility essentially serves as a giant battery bank, accepting excess PV production during the day and providing electricity at night or during cloudy weather. In utility-serviced areas where outages are common or lengthy, having some on-site battery backup can make sense. However, carefully considering the maintenance, cost, and potential hazards of a battery bank is important. Selecting only what loads are critical to maintain during grid outages will keep the number of batteries needed—and battery cost—down. Off-grid design is the most appropriate when there is no access to the grid and is not typically considered for homes that are already connected to the utility. Often, remote properties can be powered from an off-grid PV system for less than the cost of the utility line extension, making it the most economical option.